Mumbai Airport’s runway closure is starting to become a yearly thing now. They had shut both the runways for maintenance from October 18, 2016, through November 28, 2016. Then the main runway was shut for six days a week from February 2017 through April 2017. Then for six hours on October 23, 2018. Now Mumbai airport will close both the runways, three days a week, in February and March 2019.
From February 7 to March 30, 2019, both the runways will close for six hours from 11 am to 5 pm on Tuesdays, Thursdays and Saturdays. This closure will be due to re-carpeting and overlay work of the runway intersection. While the news about a possible closure was out in September 2018, a NOTAM (Notice to Airmen) was issued last month.
Already, airlines have adjusted their schedule accordingly, and no flights are available during the closure period. Vistara has already issued a travel update regarding affected flights. Even Jet Airways which is the largest carrier out of Mumbai has put out a list of affected flights.
International airlines such as Kenya Airways have pushed back their affected flights to later departure time. Check your tickets and confirm with the airlines in case your flight was scheduled during the affected period. I’d expect airfares to go up again due to reduced flights at this time.